Introduction to Earth Science

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Introduction to Earth Science

• Chapter 1

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Essential Questions

1. What does an Earth Scientist study?
2. What information do various maps give to an Earth
   Scientist?
3. How do Earth Scientists (and all scientists) seek
   knowledge?

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Overview of Earth Science

• Earth science is the name of the group of
  sciences that deals with Earth and its neighbors
  in space.
• Earth science is divided into four broad
  categories

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The Earth Sciences

• Geologythe study of the solid Earth
• Oceanographythe study of the Earths oceans
• Meteorologythe study of the Earths atmosphere
• Astronomythe study of the Earths place in the
  universe
• Environmental Science the study of how an
  organism interacts with its environment

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A View of the Earth

• Earth can be thought of as consisting of four
  major spheres
• Hydrosphere
• Atmosphere
• Geosphere
• Biosphere

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Earths Major Spheres

• The hydrosphere includes all liquid water on
  Earthboth saltwater and fresh water.
• The atmosphere consists of the gaseous envelope
  surrounding the Earth.
• Although the atmosphere extends more than 100km
  up, 90 is within 16km of the surface.

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Earths Major Spheres

• The biosphere includes all life on Earth.
• The biosphere is concentrated in a zone that
  extends from the ocean floor upward several
  kilometers in the atmosphere.
• The geosphere consists of the solid parts of the
  planet and is not uniform.
• Based on differences in composition it is divided
  into three main regions, the core, the mantle,
  and the crust.

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Scientific Inquiry

• All science is based on two big assumptions
• The universe behaves in a consistent and
  predictable manner.
• Through study, we can understand this behavior.

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Hypothesis

• Once observations have been made and data
  gathered, scientists try to explain how or why
  things happen in the manner observed.
• They state a possible explanation called a
  scientific hypothesis.

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Theory

• Once further observations have been made and/or
  tests performed, scientists either accept,
  modify, or reject their hypothesis.
• The hypothesis is elevated to a Scientific Theory
  once it has been well tested and accepted by the
  scientific community as the best explanation of
  observable facts.

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Scientific Method

• Problem/Question
• Observation/Research
• Formulate a Hypothesis
• Experiment
• Collect and Analyze Results
• Conclusion
• Communicate the Results

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Steps of the Scientific Method

• 1. Problem/Question Develop a question or
  problem that can be solved through
  experimentation.

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Steps of the Scientific Method

• 2. Observation/Research Make observations and
  research your topic of interest.

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Do you remember the next step?
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Steps of the Scientific Method

• 3. Formulate a Hypothesis Predict a possible
  answer to the problem or question.
• Example If soil temperatures rise, then plant
  growth will increase.

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Steps of the Scientific Method

• 4. Experiment Develop and follow a procedure.
• Include a detailed materials list.
• The outcome must be measurable (quantifiable).

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Steps of the Scientific Method

• 5. Collect and Analyze Results Modify the
  procedure if needed.
• Confirm the results by retesting.
• Include tables, graphs, and photographs.

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Steps of the Scientific Method

• 6. Conclusion Include a statement that accepts
  or rejects the hypothesis.
• Make recommendations for further study and
  possible improvements to the procedure.

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Steps of the Scientific Method

• 7. Communicate the Results Be prepared to
  present the project to an audience.
• Expect questions from the audience.

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Think you can name all seven steps?
Problem/Question
Observation/Research
Formulate a Hypothesis
Experiment
Collect and Analyze Results
Conclusion
Communicate the Results
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• Lets put our knowledge of the Scientific Method
  to a realistic example that includes some of the
  terms youll be needing to use and understand.

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Problem/Question

• John watches his grandmother bake bread. He ask
  his grandmother what makes the bread rise.
• She explains that yeast releases a gas as it
  feeds on sugar.

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Problem/Question

• John wonders if the amount of sugar used in the
  recipe will affect the size of the bread loaf?

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Observation/Research

• John researches the areas of baking and
  fermentation and tries to come up with a way to
  test his question.
• He keeps all of his information on this topic in
  a journal.

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• John talks with his teacher and she gives him a
  Experimental Design Diagram to help him set up
  his investigation.

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Formulate a Hypothesis

• After talking with his teacher and conducting
  further research, he comes up with a hypothesis.
• If more sugar is added, then the bread will rise
  higher.

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Hypothesis

• The hypothesis is an educated guess about the
  relationship between the independent and
  dependent variables.
• Note These variables will be defined in the next
  few slides.

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Do you know the difference between the
independent and dependent variables?
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Independent Variable

• The independent, or manipulated variable, is a
  factor thats intentionally varied by the
  experimenter.
• John is going to use 25g., 50g., 100g., 250g.,
  500g. of sugar in his experiment.

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Dependent Variable

• The dependent, or responding variable, is the
  factor that may change as a result of changes
  made in the independent variable.
• In this case, it would be the size of the loaf of
  bread.

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Experiment

• His teacher helps him come up with a procedure
  and list of needed materials.
• She discusses with John how to determine the
  control group.

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Control Group

• In a scientific experiment, the control is the
  group that serves as the standard of comparison.
• The control group may be a no treatment" or an
  experimenter selected group.

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Control Group

• The control group is exposed to the same
  conditions as the experimental group, except for
  the variable being tested.
• All experiments should have a control group.

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Control Group

• Because his grandmother always used 50g. of
  sugar in her recipe, John is going to use that
  amount in his control group.

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Constants

• Johns teacher reminds him to keep all other
  factors the same so that any observed changes in
  the bread can be attributed to the variation in
  the amount of sugar.

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Constants

• The constants in an experiment are all the
  factors that the experimenter attempts to keep
  the same.

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Can you think of some constants for this
experiment?
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Constants

• They might include
• Other ingredients to the bread recipe, oven used,
  rise time, brand of ingredients, cooking time,
  type of pan used, air temperature and humidity
  where the bread was rising, oven temperature,
  age of the yeast

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Experiment

• John writes out his procedure for his experiment
  along with a materials list in his journal. He
  has both of these checked by his teacher where
  she checks for any safety concerns.

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Trials

• Trials refer to replicate groups that are exposed
  to the same conditions in an experiment.
• John is going to test each sugar variable 3 times.

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Collect and Analyze Results

• John comes up with a table he can use to record
  his data.
• John gets all his materials together and carries
  out his experiment.

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Size of Baked Bread (LxWxH) cm3
Size of Bread Loaf (cm3) Trials
Amt. of Sugar (g.) 1 2 3 Average Size (cm3)
25 768 744 761 758
50 1296 1188 1296 1260
100 1188 1080 1080 1116
250 672 576 588 612
500 432 504 360 432
Control group
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Collect and Analyze Results

• John examines his data and notices that his
  control worked the best in this experiment, but
  not significantly better than 100g. of sugar.

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Conclusion

• John rejects his hypothesis, but decides to
  re-test using sugar amounts between 50g. and 100g.

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Experiment

• Once again, John gathers his materials and
  carries out his experiment.
• Here are the results.

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Can you tell which group did the best?
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Size of Baked Bread (LxWxH) cm3
Size of Bread Loaf (cm3) Trials
Amt. of Sugar (g.) 1 2 3 Average Size (cm3)
50 1296 1440 1296 1344
60 1404 1296 1440 1380
70 1638 1638 1560 1612
80 1404 1296 1296 1332
90 1080 1200 972 1084
Control group
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Conclusion

• John finds that 70g. of sugar produces the
  largest loaf.
• His hypothesis is accepted.

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Communicate the Results

• John tells his grandmother about his findings and
  prepares to present his project in Science class.